As an outer mirror attached to the side of vehicle body, it is, in general, adapted to use a folding outer mirror, which is rotated between a normal position to direct a mirror surface of a mirror approximately at a right angle relative to the side of vehicle body and a folded position to be folded in the side of vehicle body. In the folded position, the mirror surface is, in general, arranged to direct a rear position opposing to the side of vehicle body by rotating the mirror assembly in a direction of vehicle body. The folding outer mirror is constituted to rotate to a forward retracted position prepared for outside forces such as an unexpected crash or contact from the rear side of car such that the mirror assembly can be retracted by rotating in the forward.
The folding outer mirror is provided with a mirror base extending outside from the side surface of vehicle body and a mirror assembly being rotatably mounted in the mirror base. The folding outer mirror is provided with a positioning mechanism to stop the mirror assembly at a normal position and a stopper mechanism to stop the mirror assembly at a folded position or a retracted position when the mirror assembly rotates from the normal position to a rear folded position or a forward retracted position.
The stopper mechanism is constituted to compose, for example, of an arcuate groove formed in the mirror base and a convex part provided in the mirror assembly and to move the convex part along the arcuate groove. For example, it may be referred to Japanese Patent unexamined laid-open publication No. 9806 of 2004 or No. 282088 of 2006. In such a stopper mechanism, when the mirror assembly is folded in a folded position, one side end surface of the convex part (an engaging surface) is in contact with a circumferential end surface (an engaging surface) of the arcuate groove, thus to regulate a movement of the mirror assembly. When the mirror assembly is rotated to a retracted position, the other side end surface of the convex part (an engaging surface) is in contact with the other end (an engaging portion), thus to regulate a movement of the mirror assembly. As above mentioned, when the folding outer mirror is rotated rearwards or forwards from a normal position, the folding outer mirror is designed to stop at a folded position or a retracted position by contacting each side end surface of the convex part with one end or the other end of the arcuate groove. The engaging surface as contacted and engaged with each other is formed on a plane crossing at a right angle relative to a rotating direction of the mirror assembly.